How big was the comet that hit the dinosaurs

For 50 pointsfredrika's science teacher asked her to bring in three abiotic items from her backyard ecosystem. which of the following groups of items should she bring? a. a lightning bug, a plug of grass, and a wormb. a smooth rock, some red dirt, and an empty bird's nestc. a ladybug, a spider, and some water from a mud puddled. a caterpillar, a pine cone, and a piece of a robin's egg